The human body consists of many different anatomical structures. Among these anatomical structures are the blood vessels which circulate blood throughout the body, i.e., the arteries which deliver oxygenated blood to the end tissues and the veins which return oxygen-depleted blood from the end tissues.
In some cases, a blood vessel can become weakened, thereby causing the side wall of the blood vessel to balloon outwardly so as to create an aneurysm. See, for example, FIGS. 1-3, which show various types of aneurysms, e.g., a fusiform aneurysm (FIG. 1), where the aneurysm extends around a substantial portion of the circumference of a blood vessel; a lateral aneurysm (FIG. 2), where the aneurysm extends out of a limited portion of the side wall of a blood vessel, with a well-defined neck; and a bifurcation aneurysm (FIG. 3), where the aneurysm extends out of the apex of a bifurcation of a blood vessel. For purposes of the present invention, all of these aneurysms (e.g., fusiform aneurysms, lateral aneurysms and/or bifurcations aneurysms) are considered to extend out of the side wall of a blood vessel.
Aneurysms can present a serious threat to the patient, since they may enlarge to the point of rupture, thereby resulting in a rapid and uncontrolled loss of blood. Depending upon the size and location of the aneurysm, the aneurysm can be life-threatening.
By way of example but not limitation, an intracranial aneurysm can be fatal if rupture occurs. Given the life-threatening nature of such intracranial aneurysms, these aneurysms have traditionally been treated with an open craniotomy and microsurgical clipping. This procedure generally involves placing a small titanium clip across the neck of the aneurysm, thus isolating the aneurysm from blood flow and inhibiting subsequent rupture (or re-rupture). This clipping procedure is typically done under direct visualization, using an operating microscope.
More recently, minimally-invasive techniques have also been used to treat both ruptured and un-ruptured brain aneurysms. These minimally-invasive techniques generally employ interventional neuroradiological procedures utilizing digital fluoroscopy. More particularly, these interventional neuroradiological procedures generally use X-ray visualization to allow the surgeon to place a microcatheter within the dome of the aneurysm. With the microcatheter in place, detachable coils are then deployed within the dome of the aneurysm, thereby reducing blood velocity within the dome of the aneurysm and causing thrombosis of the aneurysm so as to prevent subsequent rupture (or re-rupture). However, this coil-depositing procedure has a number of drawbacks, including the risk of coil herniation into the lumen of the blood vessel; the risk of coil migration out of the aneurysm and into the blood vessel, with subsequent downstream migration; the risk of aneurysm rupture; etc.
As a result, a primary object of the present invention is to provide a new and improved device, adapted for minimally-invasive, endoluminal delivery, which may be used to restrict blood flow to an aneurysm while still maintaining substantially normal blood flow through the blood vessel.
Another object of the present invention is to provide an expandable spherical structure, comprising an open frame with a flow-restricting face (i.e., a closed face or a face having a high strut density), which may be used to restrict flow through an opening in a side wall of a blood vessel while still maintaining substantially normal blood flow through the blood vessel.
Another object of the present invention is to provide an expandable spherical structure, comprising an open frame with a flow-restricting face (i.e., a closed face or a face having a high strut density), which may be used to reinforce a weakness in a side wall of a blood vessel while still maintaining substantially normal blood flow through the blood vessel.
Another object of the present invention is to provide an expandable spherical structure, comprising an open frame with a flow-restricting face (i.e., a closed face or a face having a high strut density), which may be used to restrict flow through an opening in the side wall of a lumen other than a blood vessel, and/or so as to reinforce a weakness in a side wall of a lumen other than a blood vessel, while still maintaining substantially normal flow through the lumen.
Another object of the present invention is to provide an expandable spherical structure which may be used to facilitate the deployment of detachable coils and/or other embolic material into the interior of an aneurysm while still maintaining substantially normal flow through the blood vessel.